OPTICAL-ABSORPTION PROPERTIES OF SILVER ATOMS IN GAMMA-IRRADIATED AQUEOUS, 2-METHYLTETRAHYDROFURAN, AND ETHANOL SOLUTIONS AT LOW-TEMPERATURES

Aqueous, 2-methyltetrahydrofuran, and ethanol solutions containing Ag were irradiated at 4 or 77 K with gamma-rays. The main absorption ban ds observed in the region of 350-450 nm for these solutions are ascrib ed to Ag-0. The absorption bands consist of several components, which are ascribed to Ag-0 trapped in cavities with different structures. As the annealing temperature was raised, the bands at the shorter wavele ngths became predominant in the aqueous solution. In addition to the m ain absorption bands, two or three absorption bands were observed in t he vicinity of 300 nm for the solutions other than the aqueous solutio n at 77 K. In comparison with the spectra of Ag-0 in solid rare gases, we tentatively ascribe the bands near 300 nm to Ag-0 trapped in a lar ge cavity in which shell structure consists of C-H groups.